IRDL support for custom dialect definition

[Moxinilian]

I am currently adding IRDL support for custom dialect definition to the C API, and once this has landed I'd like to add it to melior as well. Ideally a macro to generate useful Rust types from IRDL definitions would be really nice, but simply allowing to register custom dialects specified in IRDL would already be sufficient.

[Moxinilian]

As an update: I have managed to make this work on my fork of melior that uses LLVM 19. I assume there is no interest in LLVM 19-only features for now, so once LLVM 19 is released and supported in melior, I'll be able to submit a PR.

[TyrsDev]

This sounds excellent, @Moxinilian. I'm hoping for custom dialect support in melior soon. Do you have any resources or documentation available where I could see how this would be used in melior?

[Moxinilian]

Yes, basically it's just a matter of exposing mlirLoadIRDLDialects, which takes a ModuleOp and loads any IRDL dialect defined in it.

[ProfFan]

LLVM 19.1.0 is out, https://github.com/llvm/llvm-project/releases/tag/llvmorg-19.1.0

[edg-l]

Made this in #640